In the prior art liquid oscillator nozzles as disclosed in the application of Harry C. Bray, Jr., entitled "Cold Weather Fluidic Fan Spray Devices And Method" U.S. application Ser. No. 959,112 filed Nov. 8, 1978, now U.S. Pat. No. 4,463,904, (the disclosure of which is incorporated herein by reference) and the oscillators disclosed in Bauer U.S. Pat. Nos. 4,157,161, 4,184,636 and Stouffer et al U.S. Pat. Nos. 4,151,955 and 4,052,002, and Engineering World, December 1977, Vol. 2, No. 4 Page 1, (all of which are incorporated herein by reference) liquid oscillator systems are disclosed in which a stream of liquid is cyclically deflected back and forth, and in the case of U.S. Pat. No. 4,157,161, Engineering World, and the above application of Bray, the liquid is a cleaning liquid compound directed upon the windshield of an automobile. In those which have the coanda effect wall attachment, or lock-on (Engineering World, for example) there is a dwell at the ends of the sweep which tends to make the fan spray heavier at ends of the sweep than in the middle. Such system works very well where a single nozzle is used to provide a fan spray from the center of the windshield as in the system disclosed in Engineering World system.
The basic object of the present invention is to provide a liquid oscillator element which produces a swept jet fan spray in which the liquid droplets are relatively uniform throughout the fan spray thereby resulting in a more uniform dispersal of the liquid.
For example, in a preferred embodiment, the liquid is a windshield washer fluid which is sprayed on an automobile windshield and the uniform droplets provide a better cleaning action. In addition, the oscillator in the present invention retains the desirable low pressure start features of the prior art as well as the cold weather start characteristics of the oscillator disclosed in the above mentioned Bray patient application.
Thus, a further object of the invention is to provide an improved liquid oscillator for automobile windshield washer systems.